Improvement in burglar-alarms



T. POWELL. Bufglar-Alarm.

No. 222,949. Patented Dec. 23, 1879 UNITED STATES PATENT OFFICE.

V THOMAS POWELL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE- HALF OF HIS RIGHT TO CHARLES D. MIDDLETON, OF SAME PLACE.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 222,949, dated December 23, 1879; application filed September 20, 1879.

To all whom it may concern:

Be it known that I, THOMAS POWELL, of Philadelphia, Pennsylvania, have invented a new and useful Improvement in Burglar- Alarms, of which the following is a specification.

. a perspective view of part of a door and doorjamb with the alarm set ready for use; Fig. 2, the same, showing the alarm folded against the door so as to be inoperative; Figs. 3 and 4, sectional plans of the alarm-Fig. 3 showing it about to be set for use, and Fig. 4 showing it folded; Fig. 5, a perspective view of the device applied to a window sash and frame; Fig. 6, a modification of my invention; Fig. 7, a perspective view of the detonating device used in connection with the alarm.

In Figs. 1 and 2, A represents part of a door, and B part of the jamb, the door opening in the direction of the arrow. The alarm, as shown in Figs. 1, 2, 3, and 4, consists of the three plates D, D, and D the first being secured to the door A, the second plate, D, hinged at a to the plate D, and the third plate, D hinged at b to the plate D, so that the device can be adjusted to the position shown in Figs. 1 and 3, or can be folded out of the way against the door, as shown in Figs. 2 and 4.

' The detonating device (shown 1n Fig. 7) consists of two strips, :12 ac, of stiff paper, cardboard, or other equivalent material, one strip overlapping the other, and these overlapping portions being bound together by a band, y, in such a manner that one strip can be pulled away from the other, thereby creating a trio tion which causes the explosion of i'ulminate interposed between the said overlapping portions.

At and near the outer end of the plate D is a longitudinal slot, d, and at the same end of the plate are formed two lips, c e, which serve as guides for inserting the detonating device into its place at the back of the plate, and also for aiding in retaining the said device in its proper position.

In the strip 00 is made a hole, f, into which is fitted a button, f, projecting from the inner face of the plate D as shown in Fig. 3. A lug, i, Figs. 2 and 3, projects from the plate D, and when the device is folded, as in Fig. 2, this lug fitsin the slot dot the plate D and prevents the removal of the detonatin g device. The lug i also bears against the face of the door when the plates are in the position shown in Fig. 1, and serves to retain the plates in this position by preventing the plate D from turnin g on its hinge in the direction of the arrow 2.

When the instrument has to be set for causing an alarm on opening the door, the two plates D and D are folded out, as shown in Figs. 1 and 3,'so that the end ofa pin, h, Fig. 2, which has been driven into the jamb of the door, may pass through the orifice y of the strip as. One strip of the detonating device being thus held by the pin while the other strip is held by the button f of the plate D, a slight opening of the door must result in the explosion of the fulminate and the giving of the desired alarm.

Substantially the same device applied to a window is shown in Fig. 5. In this case, however, one edge instead ot the end of the plate D is hinged to a plate on the lower sash, H, and a pin, h, on the jamb I passes through a hole in one strip. of the detonating device, while the other strip is held by a button, f, on the plate D so that on raising the sash the strip .00 must be pulled from the strip 00, and an explosion of the fulniinate between the two strips must take place.

The modification, Fig. 6, is intended for givin g an alarm when the upper sash of a window is lowered. In this case the plate D is hinged to a plate secured to the lintel of the windowframe, and a pin projecting from the sash passes through the hole in the strip at of the detonating device, while the other strip is held by a button on the plate D as in the former cases, so that an explosion must take place when the sash is lowered.

The devices illustrated and described are permanent attachments, which can be folded out of the way and rendered inoperative during the day, and easily set for giving an alarm at night.

The plate D, Fig. 1, may be hinged to the door-jamb instead of to the door, in which case the pin h must be attached to the door. For instance, we may suppose A to be part of the jamb in Fig. 1, and B part of the door, open ing in a direction contrary to that pointed out by the arrow. In like manner the plate D in Fig. 5 may be hinged to the jamb, and the pin k may be attached to the sash.

I claim as my invention 1. The combination, in a burglar-alarm apparatus, of a door or window and its frame, and adetonating device with a plate hinged to said door, or window, or frame, and provided with means for retaining one end of said detonating device, and a hook or pin arranged on said frame, window, or door, in respect to said hinged plate, as described, whereby it is adapted for receiving and retaining the other end of the detonating device, all substantially as set forth.

2. The combination of the detonating device, the plate D constructed for the reception of the same, and the hinged plate D, having a lug, 2', all substantially as specified.

3. The combination of the door A, thejamb B, the hook h, and the plate D, secured to the door, with the plate D carrying the detonating device, and the intermediate plate, D, hinged to both plates D and D as set forth. In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS POWELL.

Witnesses:

ALEXANDER PATTERSON, HARRY SMITH. 

